1. Field of the Invention
This invention relates to a reflecting shade for mounting on a fluorescent tube, and more particularly to a light-weight, curved reflecting shade for mounting directly on a fluorescent tube to provide a curved reflector for reflecting downwardly substantially all of the luminous energy radiated from the upper surface of a fluorescent tube.
2. Description of the Prior Art
The price of energy, especially electrical power, has forced many conservation measures and attempts to improve the efficiency of devices consuming electricity. For example, fluorescent lights in buildings use significant electrical energy, and during the recent energy crises, various steps have been taken to reduce consumption of electrical energy by fluorescent lights. One step involved removal of one or more fluorescent tubes in light fixtures utilizing multiple fluorescent tubes. This in turn led to the use of small reflective shade devices in an attempt to increase the light output from the reduced number of fluorescent tubes.
Various reflective shades have been known in the prior art. In one embodiment, the transverse plates of the shade are designed with the apertures for the fluorescent tube, and the plates cannot be opened. Mounting of the shade thus requires removal of the fluorescent tube from its fitting. Further, this design with the transverse plates surrounding the fluorescent tube requires a clearance to the shade which limits the number of types of fluorescent fixtures in which the shade can be used.
Another retrofit apparatus for fluorescent fixtures is shown in U.S. Pat. No. 4,336,576 to Daniel B. Crabtree. The problem with such approach is that it does not provide a universally applicable device that can be applied to most existing fluorescent fixtures without requiring modification of the fixture and/or the retrofit device. Furthermore, installation of the device requires removal of all bulbs and in most if not all cases, at some modifications of the existing light fixture.
Reflective shades are known which permit mounting of the shade without requiring removal of the fluorescent tube from its fixture. These prior art shades have various short-comings. Some employ resilient clamping members that make production of the shade expensive and the clamping member can damage the fluorescent tube if appropriate care is not used.
Another reflective shade is disclosed in Danish Patent Publication No. (11). 144575 B. This shade has two substantially uniform shade halves, each of which describes a part of a curved surface parallel to the axis of the fluorescent tube. Each shade half is interconnected with a number of transversely oriented plates disposed in spaced apart relationship along the length of the shade. The lateral edges of the plates have a curvature corresponding to the curvature of the shade halves and the lateral surface of the plates are secured to the shade halves. This shade has several deficiencies including its limited width and centralized aperture for receiving and holding the fluorescent tube. Further, this prior art shade has one fixed location for receiving and holding the fluorescent tube.
Accordingly, there is a need for an improved reflecting shade that gives a wide band of uniform light output across the fixture in which it is to be used. Also, there is a need for a reflecting shade having a hanger means that is laterally movable so the hanger can be moved into position to receive and attach to the fluorescent tube wherever located in a particular light fixture.